Jason Armstrong, 29, was arrested after he entered the Northeastern District station with a loaded .22-caliber pistol, police said. Police said they also seized 24 pieces of suspected crack cocaine in clear white plastic baggies, four clear green plastic bags containing suspected heroin and two pink clear plastic bags containing suspected marijuana less than 10 grams.

Police said Armstrong was sent to the Northeastern District station. Officers smelled marijuana on Armstrong, searched him and found a loaded gun, police said. Armstrong told them he had been sent in by the BGF gang to test security, police said.

Police Commissioner Anthony Batts has called the incident alarming. Batts said he is ordering security changes throughout the department and is calling a meeting of other agency chiefs over the next few days.

"An organized gang in the city of Baltimore sent an armed suspect into our building to see our security, to test our security. That is alarming to us, to me. I am going to send a message that we are not going to cower, we're not going to back down," Batts said.

Police said Armstrong is credible and they suggested he had been put up to the task because of running afoul of the gang previously.

"He did not go in there on his free will. This person had very little option, according to his statement, which lends credibility to what a dire situation this was," Deputy Police Commissioner Jerry Rodriguez said.

Armstrong was charged with various weapons and narcotics violations. He was held at the Baltimore Central Booking and Intake Facility.

"Clearly, this was not a rumor. Clearly, this was not hyperbole. This happened," Batts said.

Last month, the FBI warned police departments nationwide that the BGF was targeting police officers.

Security has also been enhanced in neighboring Baltimore County, where Cpl. John Wachter said, "The Baltimore County Police Department has received information about an incident at the Baltimore City Police Northeast District Station this morning. In response to this, we have made necessary adjustments to our operations to ensure the safety of officers, professional staff, and visitors at our facilities."